Multiple hand effect
For a basic strategy player, there's no difference in the percentage house edge whether you play one hand or two. But there are differences...
If we compare betting $100 on one spot to betting $50 each on two spots over the same number of rounds, the expected loss for a basic strategy player is identical in these two alternatives. However, the variance will be lower on the two-hand option. That is, the net wins and losses will be generally smaller when you're betting two hands instead of one. They'll still average out to the same end-result over many hands, but there will be fewer big winning sessions and fewer big losing sessions.
The other factor that can apply here is speed of the game. Playing two hands of $50 takes more time than playing one hand of $100, so you'll get fewer hands per hour with 2x$50, and that means your expected loss per hour will be lower.